Gel extraction

One of the major ways of separating things is based on size. Agarose is kind of like jello and is particularly effective at resolving things based on size. Recently, I have been working with DNA. Essentially, I have a circular shaped piece of DNA that codes for a green protein, I want to make it a red protein instead. To do that I cut the circle into two pieces a big one coding most of the protein and a little one coding the green part. Simultaneously, I do the same thing to another circle of of DNA that has a red part. I then separate these two parts on an agarose gel and cut out the right sized bits and glue them back together. Ta da a bit of DNA to make a brand new red protein.